IDENTIFICATION OF A DROSOPHILA PRESENILIN HOMOLOG - EVIDENCE OF ALTERNATIVELY SPLICED FORMS

Some cases of Alzheimer's disease are inherited as a dominant trait in humans. To dare, mutations in three genes account for some of them: t he amyloid precursor protein (APP) and pre senilins 1 and 2 (PS-1 and PS-2, respectively). The function of the presenilins is still unclear, although they belong to a transmembrane protein-gene Family, probably involved in some signaling pathway. We report here the isolation of t he Drosophila presenilin homologue using the human PS-1 and PS-2 cDNAs as probes. Only one single gene has been detected in the Drosophila g enome and evidence for alternatively spliced forms is presented and co mpared to the isoforms reported in humans. Temporal and spatial expres sion has been assessed by Northern blot and in situ hybridization on e mbryos of different developmental stages.